Heat transfer apparatus

ABSTRACT

A heat transfer apparatus or steam boiler wherein a closed vessel of reinforced pressure resisting construction is provided with intake means for fluid or water, and exit means for heated fluid or steam. Passing through the interior of the vessel but forming a completely independent set of passages is a series of channels for intake of heat via fire, hot liquid or other means. The channels pass through and within the interior of the vessel and are physically connected to fins which extend through the interior. The fins are more closely spaced at the top and wider spaced at the bottom of the vessel. The fluid or water intake means may be provided with means to convert the fluid intake into a fine spray within the vessel. Thus a highly efficient rate of heat transfer is provided from heat source to the internally injected fluid in a relatively small vessel area suitable for small volume engines as for personal automotive vehicles and the like.

limited States Patent 1191 Mc0rmiclk 1 Jan. 15, 1974 HEAT TRANSFER APPARATUS Primary Examinerl(enneth W. Sprague [76] Inventor: 161m McCormick, 1018 Beryl St., Ammekmfred KOZak PO. Box 9368, San Dieg0,'Calif. 92109 [57] ABSTRACT [22] Filed: Aug. 4, 1972 A heat transfer apparatus or steam boiler wherein a 2] A N 278,045 closed vessel of reinforced pressure resisting construc 1 pp 0 tion is provided with intake means for fluid or water, and exit means for heated fluid or steam. Passing [521 US. Cl. 122/115, l22/367 R through the interior of the vessel but forming a com- [51] int. Cl. F22b 9/04 pletely independent set of passages is a series of chan- [58] Field Of Search 122/17, ll5, l55 R, nels for intake of heat via fire, hot liquid of other 367 367 67 A, 410 means. The channels pass through and within the interior of the vessel and are physically connected to References Cited fins which extend through the interior. The fins are UNITED STATES PATENTS more closely spaced at the top and wider spaced at the 2,625,138 1 1953 .lacoby 122/17 bottom 0f Vessel The fluid or Water intake means 3,241,530 3/1966 Blockley et al.- 122 410 y be Provided Wllh means to Convert the fluid 1,201,161 10/1916 Dwyer 122 115 X ake in o a fine spray within the vessel. Thus a highly 1,611,040 12/1926 Jahn et al.. .1 122/114 efficient rate of heat transfer is provided from heat 104,511 6/1870 Tillman 122/367 X source to the internally injected fluid in a relatively 2,448,128 8/1948 Trageser 122/367 X Small vessel area Suitable f Small volume engines as for personal automotive vehicles and the like.

i 4 Claims, 9 Drawing Figures PAIE-NTEUJWBIQH 5,7853% sum 2 or 2 v Pump HEAT TRANSFER APPARATUS BACKGROUND OF THE INVENTION This invention relates to the efficient transfer of heat from a heat-source into a fluid using a minimal amount of spatial volume to accomplish the result. More particularly, the invention embodies a fire-tube steam boiler using a unique internal configuration which optimizes the transfer of heat into a fluid such as water which is inserted into a vessel and removed as a vapor such as steam. Further, the heat-transfer apparatus described herein presents various advantages over the prior art with regard to position-sensitivity of the apparatus.

In the history of steam utilization, various methods of steam generation or heat transfer from source into a fluid have been used. Among the earlier methods have been the use of a closed vessel containing water to which has been added heat in the form of flame or fire so that when the fluid has been vaporized, an outlet pipe could be used to convey steam or vaporized fluid out of the vessel.

Later in the history of steam generation came the fire-tube boiler wherein a sealed vessel containing water had a series of sealed tubes passing through the interior and wherein fire and heat could pass up through the fire tubes to heat and water or fluid into a vapor state.

Another development in steam generation came in the form of the flash boiler wherein a coiled or other form of tubing was used to carry water or other fluid and said fluid during its passage through the tube was subjected to heat or flame causing vaporization of fluid in the tube or tubes so that the liquid intake came out as steam or vapor.

BACKGROUND: PROBLEMS OF PRIOR ART The basic problems have always been that of operat' ing efficiency or stated otherwise how much work could be developed from a heated fluid or steam per unit quantity of fuel consumed. Further involved was the problem of convenience and utility in regard to the size of the vessel required for heat transfer and its simplicity of maintenance without complicated repair and control factors.

Some of the early embodiments of a steam boiler involved a closed vessel holding water and through which fire tubes were inserted in a parallel and vertical or horizontal fashion. The fire tubes were heated with flame or even hot oil (as, for example, in the Stanley U.S. Pat. No. 678,912) for purposes of conducting sufficient heat into water in the vessel to cause rapid conversion of water to steam which could then be out-putted through a vent pipe.

One of the problems incurred in such fire-tube type boilers was the factor that the lower portions of the fire tubes were the hottest causing steam to generate at the bottom of the vessel to cause an explosive or blowup action which drove both steam and water upward to the exit vent, with resultant damage to the engine.

Another problem was the limited amount of surface area presented by the interior walls of the fire tubes within the water vessel, in addition to the limitations of prior art apparatus which required operation only in a substantially vertical position.

It is believed that analysis of an optimum internal heat transfer means has not yet been fully investigated, and the present invention attempts to provide what is considered an optimum internal heat transfer means suitable for utilization in a small confined space and so arranged as to eliminate the rapid heat transfer at the bottom of the vessel while at the same time transferring heat at a greater rate near the upper areas of the vessel interior.

SUMMARY OF THE INVENTION This invention involves a more optimium heat transfer apparatus for conversion of fluids into a vapor state and particularly water into steam by the use of an explosion-proof closed vessel. The closed vessel has heatbearing tubes inserted into it from bottom to top all in a series. Physically attached to the series of fire tubes is a series of fins brazed to each fire tube at various po sitions along the elevation of the fire tubes within the vessel. The fins occur in close proximity at the upper end of the fire tubes within the vessel, but are spaced apart at greater distances near the bottom of the vessel. Along the cross-sectional area of each fin, there are a series of semi-circular cuts or punched sections wherein the cut area is bent upward to expose an orifice shaped into a half-moon or semicircle so that fluids or steam may pass through the cross section of the fin area. A fluid intake tube is provided near the bottom of the vessel for intake of water or fluid which then makes contact with the fire tubes and fms for heat transfer. The cutouts permit steam to rise and take on more heat as it rises. At the top is a collection area where steam may collect and be taken off through an exit tube.

Another embodiment of the invention makes use of small flns brazed to each of the fire tubes but staggered alternately going from bottom to top of the interior of the vessel. These provide a greater heat transfer area and at the same time permit passages for steam or vapor to rise upward.

The vessel walls are made of high tensile strength aluminum or steel or may be of other high strength construction capable of withstanding at least 3,000 lbs. per sq. inch pressure.

DESCRIPTION OF THE DRAWINGS FIGS. 1A, 1B, and 1C show a basic embodiment of the invention wherein FIG. 1A is a cross sectional view of the boiler and its interior; FIG. 1B is a perspective or isometric drawing of the boiler without its enclosing casing; and FIG. 1C shows a top or plan view of the boiler; FIG. ID is a view in perspective of the details of one of the internal fins or fin-plates brazed to the interior tubes; FIG. IE is a variant form of the interior finplate.

FIGS. 2A, 2B, and 2C show another embodiment of the boiler wherein FIG. 2A is a cross sectional view through the interior of the casing; FIG. 2B is a perspective view of the interior tubes with fins omitting the external casing; FIG. 2C is a top or plan view of the boiler.

FIG. 3 is a cross-section view similar to FIG. IA with the fluid insertion provided in a manner suitable to form an internal spray.

DESCRIPTION As will be seen in FIG. 1A, a cross section view in elevation is illustrated.

A cylindrical receiver-casing 10 forming a sealed vessel has an inlet passage which may constitute a pipe 11 for entrance of fluid into the vessel cavity of casing 10. At the top is provided an exit passage or exit pipe 12 for removal of heated fluids, vapor, or steam.

A series of internal tubes 13 are provided to pass from bottom to top of the casing 10. The tubes 13 are open to outside heat at the bottom areas 13,, and 13,, etc. for entry of flame or heat from a burner 14 or for heat entry from any other source suitable for heat generation. At the top of the casing, the interior tubes 13 are open at 13, and 13', etc. for exhaust of the heat products passing through the tubes 13.

The tubes 13 are sealed completely so that none of the fluids passed into the casing at inlet 11 may communicate with the interior of the tubes 13.

Brazed or otherwise solidly connected to the interior tubes 13 are a series of fins 16, of which various levels are shown as 16,,, 16,, through 16,. These fins 16 may be very closely spaced toward the top of the vessel casing and spread at a greater distance apart toward the bottom, as diagrammatically shown where the distance between 16,. and 16f is considerably greater than the distance between 16,, and 16 for example.

In FIG. 1A the vessel cavity 15 provides a circumferential passage whereby a fluid, such as water may be converted to vapor phase, as steam, for passage upward and out through the exit pipe 12.

While the fins, contiguous to the internal tubes 13, are shown in a parallel fashion to the bottom wall of the casing 10, other angular configurations may also be used, such as finned configurations which pass at an angle to the interior tubes or a V-shaped configuration wherein the fins on each side of the center of the vessel slant down around the interior tubes to form a series of V shapes.

FIG. 1B shows a perspective or isometric view of the interior tubes 13 and fins 16 of FIG. 1A with the omission of the sealed casing. The tubes 13 may be constructed of copper, brass or other heat-conductive material having durable characteristics.

FIG. 1C shows a top or plan view of FIG. 1A with the inlet port 11, the exit port 12, the casing 10 and the through-passing internal tubes 13.

FIG. 1D shows the preferred form of the fins 16' which contiguously encompass the internal tubes 13. As shown therein, a series of cutouts 17 is interspersed on the surface of each fin 16, and wherein a semicircular flap 17,, is opened from the surface of fin 16 to create a semicircular opening 17,,. The flap 17, is preferably made to occupy a 45 angle to base of the fin 16'.

FIG. 1E shows another embodiment of the fins 16 and is designated 16". In this embodiment the fins 16" are formed from a circular fin-plate in such manner as to have cutouts 17 which form a lattice-structure which is solidly brazed to the interior tubes 13.

Another embodiment of the fluid vaporized or boiler and steam generator is shown in FIGS. 2A, 2B, and 2C.

As seen in FIGS. 2A and 2C, a casing 10 has the inlet port 11 and the exit port 12 entering and exiting from the sealed vessel of casing 10. Likewise similar to FIG. 1A, a series of internal tubes 13 pass through the vessel interior of FIG. 2A as will also be seen in the perspective view of FIG. 2B.

In the embodiment of FIGS. 2A, 2B, and 2C, each of the interior tubes 13 is contiguously encompassed by a series of individual fins 18 which may be spaced at close intervals along the length of each internal tube 13.

FIG. 2C shows a top or plan view ofthe casing 10, the through-passing internal tubes 13 and the contiguously individual sets of fins 18. The vessel cavity 15 in this embodiment not only provides the circumential passage as in FIG. 1A, but also the interstices between the individual fins 18 thus permitting a greater flow of vapor toward exit pipe 12.

Referring to FIG. 3, a sealed casing 10 which may be made of high-tensile steel, or other high strength material, forms a vessel having an interior cavity, 15. An intake passage 11 is provided for intake of water or other fluids on a pressurized basis due to the action ofa fluid pump 20. The fluids pumped into the internal cavity of casing 10 flow up to orifices 11,, and 11,, to be dispersed as a spray into the interior cavity 15 for contact with the interior tubes 13 and the interior fins 16.

The interior fins 16 may be preferably made of the configuration of FIG. 1D, but may also take other fin configurations, for example, as that of FIG. 1E. Heated internal fluids such as water which has become steam vapor may then exit through the exit passage pipe 12.

OPERATION Referring to FIG. 1A, a fluid such as water is pumped under pressure into the bottom of the vessel formed by casing 10. A burner or other heat application device 14 is used to apply heat to the bottom area of the casing 10 to pass heat up through openings as 13,, of the interior tubes 13 and out through the top openings as 13,, of tubes 13.

The heat conductive material of tubes 13 and the contiguously attached fins 16 rapidly distribute heat through-out all the interior areas of the interior cavity 15 of casing 10. The rapid heat transfer vaporizes the water into steam (or other fluids into vapor) which then may pass upward through the internal cavity 15 and the cutouts 17 (as shown in FIG. 1D) where they rise and create pressure which will exhaust the vapors through exit passage 12.

The configuration of the fins 16 act also as a baffle so that the interior steam pressure will not pick up and drive liquid water, or other fluids remaining in the liquid state, into the area where the exit pipe 12 is positioned. It will also be seen that the fins 16 are controlled in density of occurrence so that the heating fins occur in greater density per unit length at the top (nearer the exit pipe 12) then they do at the bottom in the area of the intake pipe 11. This configuration controls and regulates the heat density and heat transfer rate so that the hotter areas of the tubes 13 and fins 16,, and 16, (adjacent the bottom or heated area of casing 10) will not suddenly and explosively combine water with steam and drive it upward toward the exit pipe area. Thus, in this manner, there is provided a more gradual application of heat to the liquid fluid at the bottom or heat producing area of the internal cavity.

It is not essential that the tubes 13 run through the vessel cavity in a straight-line parallel fashion as shown except for possible ease of fabrication. The tubes 13 may be run through the casing interior in a coiled, helical or other form to increase the length of passage through the casing in which case the internal fin plates as 16, 16', 16" would be conformed to also contiguously make solid contact with such other configuration of tubes 13.

With reference to the embodiment shown in FIG. 3, a fluid pump 20 is used to apply the incoming fluid under pressure into the inlet pipe 11 and thence into the internal cavity R5 of casing through orifices 111,, and 11,, which cause a fine spray or mist to be injected around the interior tubes 13 and fins 16. Since the liquid fluids or mist are inserted at the top area away from the intense heat at the bottom, there would be no need for varying the density per unit length of the fins 16 as was indicated with reference to FIG. 1A. In the situation of FIG. 3, the mist or spray may preferably be usedwith the fins 16 of FIG. 1E where the mist may suffuse down through the vessel to contact the heattransferring surfaces of the lower fins and the tubes 13 after which they would be transformed into steam whose pressure would exhaust the steam through exit pipe 12.

While much of the prior art imposed the limitation of operation in a fixed vertical or a fixed horizontal position, the apparatus of the present invention permits various angular positionings in addition to certain relative freedoms of movement. With the use of flexible couplings for fluid intake etc. and by attaching the burner or other heat energy source to the vessel casing, a wide variety of operational positions of operation can be realized.

Thus, the heat transfer apparatus described herein provides an efficient yet small and compact device suitable for the confined spaces of automotive vehicles or other size-limiting applications.

What is claimed is:

1. In a thermal conversion apparatus, the combination comprising: a casing enclosing a sealed internal cavity; means for intake of fluids into said sealed cavity; means for exhaust of heated fluids from said cavity; internal passage means of heat conducting material passing through the said internal cavity, said internal passage means being physically sealed from said internal cavity; a plurality of fin-plates physically connected to said internal passage means for conducting heat energy from said internal passage means to wider areas of said internal cavity; heat energy source means for application of heat energy through said internal passage means wherein said internal passage means includes a plurality of tubes passing through said internal cavity; and

wherein said plurality of fin-plates comprise a series of fin-plates each of which contiguously encompasses each of the plurality of tubes and the density of occurrence of said fin plates adjacent said means for exhaust of heated fluids is greater than the density of occurrence of said fin-plates adjacent said means for intake of fluids.

2. In a thermal conversion apparatus, the combination comprising: a casing enclosing a sealed internal cavity; means for intake of fluids into said sealed cavity; means for exhaust of heated fluids from said cavity; internal passage means of heat conducting material passing through the said internal cavity, said internal passage means being physically sealed from said internal cavity; a plurality of fin-plates physically connected to said internal passage means for conducting heat energy from said internal passage means to wider areas of said internal cavity; heat energy source means for application of heat energy through said internal passage means wherein said fin-plates are provided with a plurality of cutout openings through which internal fluids may pass and wherein said cutout openings comprise semicircular openings having a semicircular flange residing at an acute angle to the plane of the said openings.

3. In a heat transfer apparatus for the optimum transfer of heat energy into intaken fluids, the combination comprising: a casing enclosing a sealed internal cavity; a first passage for intake of fluids into said cavity; a second passage for outlet of heated fluids from said internal cavity; a plurality of heat conducting tubes passing through said sealed internal cavity each of said tubes having inlet and outlet ports for passage of heat energy therethrough while yet remaining sealed from said internal cavity; a plurality of fin-plates physically connected to and encompassing each one of said plurality of heat conducting tubes wherein the plurality of finplates of any one of said heat conducting tubes are interlaced with the fin-plates of the adjacent heat conducting tubes within the internal cavity.

4. The apparatus of claim 3 including heat source means adjacent the inlet ports of said heat conducting 

1. In a thermal conversion apparatus, the combination comprising: a casing enclosing a sealed internal cavity; means for intake of fluids into said sealed cavity; means for exhaust of heated fluids from said cavity; internal passage means of heat conducting material passing through the said internal cavity, said internal passage means being physically sealed from said internal cavity; a plurality of fin-plates physically connected to said internal passage means for conducting heat energy from said internal passage means to wider areas of said internal cavity; heat energy source means for application of heat energy through said internal passage means wherein said internal passage means includes a plurality of tubes passing through said internal cavity; and wherein said plurality of fin-plates comprise a series of fin-plates each of which contiguously encompasses each of the plurality of tubes and the density of occurrence of said fin plates adjacent said means for exhaust of heated fluids is greater than the density of occurrence of said fin-plates adjacent said means for intake of fluids.
 2. In a thermal conversion apparatus, the combination comprising: a casing enclosing a sealed internal cavity; means for intake of fluids into said sealed cavity; means for exhaust of heated fluids from said cavity; internal passage means of heat conducting material passing through the said internal cavity, said internal passage means being physically sealed from said internal cavity; a plurality of fin-plates physically connected to said internal passage means for conducting heat energy from said internal passage means to wider areas of said internal cavity; heat energy source means for application of heat energy through said internal passage means wherein said fin-plates are provided with a plurality of cutout openings through which internal fluids may pass and wherein said cutout openings comprise semicircular openings having a semicircular flange residing at an acute angle to the plane of the said openings.
 3. In a heat transfer apparatus for the optimum transfer of heat energy into intaken fluids, the combination comprising: a casing enclosing a sealed internal cavity; a first passage for intake of fluids into said cavity; a second passage for outlet of heated fluids from said internal cavity; a plurality of heat conducting tubes passing through said sealed internal cavity each of said tubes having inlet and outlet ports for passage of heat energy therethrough while yet remaining sealed from said internal cavity; a plurality of fin-plates physically connected to and encompassing each one of said plurality of heat conducting tubes wherein the plurality of fin-plates of any one of said heat conducting tubes are interlaced with the fin-plates of the adjacent heat conducting tubes within the internal cavity.
 4. The apparatus of claim 3 including heat source means adjacent the inlet ports of said heat conducting tubes. 